<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>It is certainly true that strong programs today are weaker at semeai
than people of the same rating. This must mean that the programs are stronger
in other areas than equal ranked people. This gives me hope that when Many
Faces plays semeai properly it will get a big jump in strength.<o:p></o:p></span></p>

<p class=MsoNormal>Don, as you say, humans are very good at discerning patterns
- and the game of Go is all about patterns. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Now, in some cases, the pattern-matching ability can lead
humans astray, but in other cases, it's a done deal. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>For example, we hashed over the concept of nakade a while
back. These are patterns which strong humans recognize at a glance. Groups with
certain shapes are mathematically, provably, totally, dead beyond hope,
assuming proper play. At that time, many programs were weak in that area. Now,
strong programs usually do not fall into such simple traps.<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>In addition to "dead beyond hope" and
"certainly alive", strong humans also recognize "can live with
ko" and "seki" shapes - again, beyond a shadow of a doubt, as
mathematically certain as the sunrise in the morning. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>The analogy with the stock market misses the mark because
the stock market has many millions of independent actors ( the human beings who
make buy and sell decisions ) who act upon many billions of facts, most of
which are inaccessible to the punditocracy who try to make sense of the markets.
(would-be pundits are also often handicapped by inferior models, but that's
another tale.)<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Go is a game of complete information played by exactly two
players, if we ignore rengo or phantom variants; when the position is
simplified enough ( something which strong players actively seek ), the result
is mathematically provable - and well within the limits of what humans can do
with their pattern recognition facilities. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>The topic here is that of large semeai; many games have
shown that programs are vulnerable to misjudging the outcome; Darren Cook has
written up a page describing the problem with random playouts and complex
semeai which depend upon precise move ordering. In many cases, semeai are won
or lost by a single play, and one must play A, B, C, D precisely in order, in
response to any one of Z, Y, W, X, etc. A large class of problems depend on
"if my group A loses a liberty, I must take a liberty from group B in
such-and-such order." Strong humans read out these problems and play them
correctly. Strong programs have been observed to fail.<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Many well-known joseki create a local situation with such
"win by 1" capturing races. Usually, the person who loses the local
race gains something - "influence" or "thickness" in
compensation; strong professional players consider these sequences to lead to
equal results for both players. If a player takes that compensation, converts
it to cash ( territory ), and also manages to swindle a program out of winning
the local semeai, the player can easily win; it's like being able to write off
a $500,000 mortgage and keep the house, because the lender made a mistake in
the paperwork.<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>It used to be fairly easy to set up a ladder and a
ladder-breaker, and programs would still play out the ladder as if the ladder
breaker were not present - a huge misconception. Strong programs don't seem to
fall into that trap anymore - but they do fall for semeai which are
conceptually similar, in a mathematically provable sense.<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>While I present a single game to illustrate my case, I
generalize from many games. It's still merely a black box analysis, however; I
leave it to the programmers to "open the box" and discover how the
internals map to the observable externals. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>There is a difference between Go and Chess. In Chess, only
one thing matters: put the other guy in checkmate, and you win, even if all you
have on the board is one king and one pawn, and the other player has a dozen
pieces. In Go, once you achieve a territorial advantage, you need only keep
what is yours. Going back a year or two, programs were not very good at keeping
what was theirs; they played odd yose moves which yielded up territory without
gaining anything in terms of improving their winrate. Semeai are the midgame
equivalent - moves which are mathematically constrained in ways which
significantly alter the real status of the game, as opposed to the hypothetical
winrate of any algorithm which does not understand those constraints. <o:p></o:p></p>

<p class=MsoNormal>Don, I'm enough of a go player to know that, in such a
position, a 2d human would trounce the kyu player, if given the middle game
position to start with - but I'd appreciate the views of a dan-level player.
MFGO in such positions often fails to take care of its groups - even
though it is far stronger than I.<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>I'm not saying you are wrong, I'm just trying to keep
everyone honest. It's just that the hair on the back of my neck sticks
up when I see an idea start to become gospel and I hope that as we figure all
of this out we are not making incorrect assumptions that will set us back.
<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Here is what bothers me about this:<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>You saw a position and said, "in such a position"
a 2d human would trounce the kyu player. Not only are you making a
judgement about a specific position (which may or may not be true), but
you are generalizing it based on what you subjectively think "such a
position" means. You have used at least 2 subjective
opinions, linked them together and use this to draw a conclusion.
(Presumably this is just a tentative conclusion, a hypothesis, which I
think is the right way to think about such things.) <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Don't forget that as humans we have very strong pattern
recognition facilities. We can see animals and all kinds of various
objects in cloud formations and studies have shown that we tend to find
patterns in random things. This often tends to make us draw conclusions
very quickly based on little evidence or just plain gut feelings as witnessed
by the large number of criminal cases that were incorrectly judged.
This is both a strength and a weakness that we have but it is the
source of massive amounts of incorrect "common wisdom."<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>How many times have programmers here observed something
wrong with the way their program plays, made a judgement about WHY the
program is playing badly, and then implemented a fix which clearly addresses
the problem they think they are seeing - and lo and behold the program is now
weaker? It was worth a try but it's way too easy for such a chain
of reasoning to be wrong. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>If you really want to see my point in action, watch
the stock market and the way each days activity is explained at the end of the
day. They will say something like, "The nasdaq today
was down based on fears of recession." The stock market is
incredibly complex, and yet the analysts ALWAYS seem to know the exact
explanation for why it went up or down some slight amount. And
that explanation is presented as a statement of fact, the reason why.
<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Sorry I'm being so picky about this but it drives me crazy,
it's one of my peeves. You didn't do anything wrong :-)<o:p></o:p></p>

<p class=MsoNormal>Dave Fotland himself has observed similar results; there are
many game records to back up this contention. A while back, I posted about a
player who has a very high winrate against MFGO - it looked like his account
did nothing else but play computer programs. <o:p></o:p></p>

<p class=MsoNormal>If you can keep track of things at blitz speed, and set up
complicated fights with large unsettled groups, and patiently encroach on a
program's eyespace ( even DDK players know that a dragon, however large, still
requires two eyes to live ), you can often give a program a good drubbing.<br>
<o:p></o:p></p>

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<p class=MsoNormal>Earlier, we had a post regarding a shogi program which
combines the votes of four other programs. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Given that processor cores are now abundant, and that UCT
programs have trouble using all that horsepower, I wonder if some cores should
look at the board in an entirely different way and, every now and then,
generate "Danger ,Will Robinson" signals which trump the usual
winrate algorithms - or at least tweak them toward safety moves. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Is there a way to combine such disparate information into a
coherent picture of the board? <o:p></o:p></p>

<p class=MsoNormal>This is a curious game - a 3 stone game betwixt ManyFaces
and a 2 kyu player. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>It looks to my eye as if MFGO was well ahead in the middle
game, yet managed to snatch defeat from the jaws of victory. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Black has many unsettled groups; usually a stronger player
causes much grief in situations like this, but black managed to turn around and
swallow up not one but several white groups. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Most interesting. I think this confirms an earlier thread -
when there are several semeai on the board, MCT-based strategies get into
difficulties. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Are you sure of this? I think it is human
nature to try to make sense of things and create general rules and principles
to explain what we think we may be observing. It's also human nature to
often be wrong about it. The first time an idea is skillfully
presented it tends to carry extra (sometimes undeserved) weight because
everyone else interprets what they see in terms of that and it gets repeated
over and over till it becomes the de-facto sound bite
that propagates itself. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>Maybe it's completely true and there is no dispute or it's
obvious - unfortunately I'm not a go player so I'm in no position to add my 2
cents but I would be very cautious about making general statements about
the relative strengths and weaknesses of humans compared to computers.
<o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>I know from experience with chess for many decades that
peoples perception of the computers strengths and weaknesses were constantly
misinterpreted, very often based on a just a game or two someone played.
People were just trying to make sense of it, but they got it
wrong a lot. In one case in the 80's my program played a master
and lost tactically and believe it or not the master felt the program was
strong positionally but weak tactically (because he beat it with a tactical
shot) even though we now understand it's completely the opposite.
The truth of the matter was that the computer was simply a lot weaker
than this particular player so it was inferior all the way around. <o:p></o:p></p>

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<p class=MsoNormal><o:p> </o:p></p>

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<p class=MsoNormal>If your supposition is true, then it's a good thing to know
because perhaps it can be addressed. Or it might end up being one
of those things that diminishes in importance over time as computers get
generally stronger and stronger. In chess, computers have always
been weaker in true positional understanding (even to this day) but we have
added so many layers of strength that this weakness is only a relative thing.
It's weaker than other parts of it's game, but not so weak that
anyone can easily take advantage of it. Most computer games resemble
Grandmaster games in the quality of positional play.<o:p></o:p></p>

<p class=MsoNormal>I think strong human players tend to have a better grasp of
"this particular fight is settled, no need to study it further until a
liberty is removed (in which case respond now!); let's focus on this other
fight instead . . ."<o:p></o:p></p>